Which command is used to switch to the XY plane in CNC milling?

The command that is used to switch to the XY plane in CNC milling is G17. This command specifically sets the active plane of operation for circular interpolation to the XY plane. In CNC programming, defining the working plane is critical for ensuring that commands for milling operations, such as circles or arcs, are executed correctly relative to the coordinate system.

Using G17 allows the CNC machine to understand that any subsequent commands intended to create circular movements will be based on the XY axis, which is fundamental for machining parts accurately. This is essential for operators to avoid programming errors that could lead to incorrect tool paths.

The other commands serve different functions: G20 is used to set units to inches, G40 is for canceling tool radius compensation, and G43 is used for tool height offset. These commands do not relate to the selection of the working plane, highlighting the specificity of G17 in establishing the XY plane for milling operations.